These 3 dots; I want to be able to click them to open/close the code. I searched quite a bit and found nothing about having them open/close with mouse. If they can be opened/closed with keyboard as well even better, but mainly I want to with mouse.
Outline mode works well for this. I use my own small outli package to set this up automatically with nice formatting and “speed key” access at the beginning of headlines. Tab to fold.